|Intersymbol Interference Investigations Using a 3D Time-Dependent Traveling Wave Tube Model - Kory, Carol L.|
For the first time, a time-dependent, physics-based computational model has been used to provide a direct description of the effects of the traveling wave tube amplifier (TWTA) on modulated digital signals. The TWT model comprehensively takes into account the effects of frequency dependent AM/AM and AM/PM conversion; gain and phase ripple; drive-induced oscillations; harmonic generation; intermodulation products; and backward waves...
Keywords: SPACE SHUTTLE BOOSTERS; THERMAL PROTECTION; COATINGS; ALUMINUM; TEST FACILITIES; TESTS
|Jerky loads on surface-hardened gears - Rettig, H.|
Damage occurs again and again in practice in the form of transmissions with surface hardened gears which break after a very long operating time (explained by seldom occurring jerky loads). Gear drives are frequently exposed to jerky stresses which are greater than their fatigue limit. These stresses are considered in gear calculations, first, by shock factors when the transmission is to be designed as high endurance with regard to overloads and, second, in the form of operating ratios when the d...
Keywords: FOUNDATIONS; THERMAL PROTECTION; THIN PLATES; SPACECRAFT CONSTRUCTION MATERIALS
|Foamglas in Thin Wall and Sandwich Panel Construction - Pittsburgh Corning Corporation|
Trade catalog, Text, Illus, Photographs, CCA ID: 89-B2714, ca. 1954, 12 p, 28 cm
Keywords: Glass; Insulation; Division 07; Thermal and Moisture Protection; Thermal Protection
|Protective cooling by a multislot and network-type injection into a turbulent boundary layer - Kutateladze, S. S.|
Protective cooling of insulated plane surface by gas injection into turbulent boundary layer of incident flow through slot system
Keywords: COOLING; THERMAL PROTECTION; TURBULENT BOUNDARY LAYER; GAS INJECTION; INJECTION; SLOTS; SURFACE COOLING; THERMAL PROTECTION; TURBULENT BOUNDARY LAYER; GAS INJECTION; SURFACE COOLING
|ANALYSIS OF THERMAL-PROTECTION SYSTEMS FOR SPACE-VEHICLE CRYOGENIC-PROPELLANT TANKS - Knoll, R. H.|
Analysis of thermal-protection systems for space vehicle cryogenic propellant tanks
Keywords: CRYOGENIC FLUID STORAGE; SPACE VEHICLE; THERMAL PROTECTION; CRYOGENIC ROCKET PROPELLANTS; HEAT TRANSFER; PROPELLANT TANKS; SPACECRAFT; STORAGE TANKS; THERMAL PROTECTION; CRYOGENIC PROPELLANT; PROPELLANT TANK
|Quantitative Infrared Spectroscopy of Minor Constituents of Earth's Atmosphere - Chackerian, Charles, Jr.|
Infrared spectroscopic techniques have become extremely powerful tools for use in achieving a number of observational objectives in understanding and monitoring the health of Earth s atmosphere. Prerequisite to designing appropriate instruments well as to interpreting the observations that monitor the important molecular species, quantitative laboratory spectroscopic measurements must be done. measurements provide (1) line and band intensity values that are needed to establish limits of detectab...
Keywords: X-34 REUSABLE LAUNCH VEHICLE; THERMAL PROTECTION; AEROTHERMODYNAMICS; ABLATIVE MATERIALS; RUDDERS; THERMAL ANALYSIS; NAVIER-STOKES EQUATION
|Solutions Network Formulation Report. Landsat Data Continuity Mission Simulated Data Products for Bureau of Land Management and Environmental Protection Agency Abandoned Mine Lands Decision Support - Estep, Lelan|
Presently, the BLM (Bureau of Land Management) has identified a multitude of abandoned mine sites in primarily Western states for cleanup. These sites are prioritized and appropriate cleanup has been called in to reclaim the sites. The task is great in needing considerable amounts of agency resources. For instance, in Colorado alone there exists an estimated 23,000 abandoned mines. The problem is not limited to Colorado or to the United States...
Keywords: BOUNDARY LAYER TRANSITION; CORRELATION; THERMAL STRESSES; AEROTHERMODYNAMICS; CALIBRATING; LEADING EDGES; TURBULENCE; BOUNDARY LAYERS; THERMAL PROTECTION; PROTUBERANCES
|Enabling Exploration - NASA Ames Video Group|
An overview of Ames Research Center and its research activities in support of NASA Exploration programs
Keywords: Ames; Ames Research Center; space exploration; technologies; thermal protection; supercomputing; NASA Research Park; intelligent systems
|Simulation study of three instrument displays to assist in airplane thrust management - Mc Laughlin, M. D|
Simulation study of three instrument displays to assist airplane thrust management
Keywords: BALANCE; THERMAL PROTECTION; HEAT SHIELDING; HEAT TRANSFER; LOADS (FORCES); VACUUM CHAMBERS
|ELECTRICITY OF CLOUDS - IMYANITOV, I. M.|
RECENT STUDIES OF THE ELECTRICAL STRUCTURE OF CLOUDS, PROCESSES LEADING TO THEIR ELECTRIFICATION, AND THE POSSIBILITY OF CONTROLLING THEIR FORMATION BY ELECTRICAL MEANS ARE REVIEWED. THE ELECTRICAL PROPERTIES OF STRATIFORM CLOUDS, CONVECTIVE CLOUDS WITHOUT RAIN, AND CUMULONIMBUS CLOUDS ARE DESCRIBED. THE ELECTRIFICATION OF PARTICLES IN CLOUDS AND PRECIPITATION, ACCUMULATION OF SPACE CHARGES IN CLOUDS, AND THE INFLUENCE OF THE ELECTRICAL CHARACTERISTICS OF A CLOUD ON ITS DEVELOPMENT ARE CONSIDERE...
Keywords: AIRFRAME MATERIALS; COMPOSITE MATERIALS; FIBERS; THERMAL PROTECTION; ATMOSPHERIC ENTRY; SPACECRAFT DESIGN
|Thermal Protection System - NASA|
Visitors to the Future Missions tent learn about the Thermal Protection System (TPS) for the Orion Crew Exploration Vehicle that will take astronaut crews to the International Space Station and will later return humans to the Moon.
Keywords: Thermal Protection System; What -- Orion; What -- International Space Station (ISS); What -- Moon
|Upward Flame Spread Over Thin Solids in Partial Gravity - Feier, I. I.|
The effects of partial-gravity, reduced pressure, and sample width on upward flame spread over a thin cellulose fuel were studied experimentally and the results were compared to a numerical flame spread simulation. Fuel samples 1-cm, 2-cm, and 4-cm wide were burned in air at reduced pressures of 0.2 to 0.4 atmospheres in simulated gravity environments of 0.1-G, 0.16-G (Lunar), and 0.38-G (Martian) onboard the NASA KC-135 aircraft and in normal-gravity tests...
Keywords: AERODYNAMIC HEATING; COMPUTER PROGRAMS; THERMAL PROTECTION; REUSABLE LAUNCH VEHICLES; NUMERICAL ANALYSIS
|Airborne profiling of ice thickness using a short pulse radar - Vickers, R. S.|
The acquisition and interpretation of ice thickness data from a mobile platform has for some time been a goal of the remote sensing community. Such data, once obtainable, is of value in monitoring the changes in ice thickness over large areas, and in mapping the potential hazards to traffic in shipping lanes. Measurements made from a helicopter-borne ice thickness profiler of ice in Lake Superior, Lake St...
Keywords: CARBON DIOXIDE; CRYODEPOSITS; FROST; THERMAL PROTECTION; HELIUM; LIQUID HYDROGEN; PROPELLANT TANKS; THERMAL INSULATION
|AURORAS - COLLECTION OF ARTICLES NO. 17 - ISAYEV, S. I., et al|
IONOSPHERIC AURORAL MORPHOLOGY, HEIGHT VARIATIONS, AND RELATIONSHIPS TO PLANETARY MAGNETIC DISTURBANCES IN PERIODS OF MINIMUM AND MAXIMUM SOLAR ACTIVITY AT VARYING LATITUDES
Keywords: ANODIC COATINGS; FLAMES; METAL SURFACES; THERMAL PROTECTION; ANODIZING; IRON ALLOYS; TEMPERATURE CONTROL
|Two Formal Gas Models For Multi-Agent Sweeping and Obstacle Avoidance - Kerr, Wesley|
The task addressed here is a dynamic search through a bounded region, while avoiding multiple large obstacles, such as buildings. In the case of limited sensors and communication, maintaining spatial coverage - especially after passing the obstacles - is a challenging problem. Here, we investigate two physics-based approaches to solving this task with multiple simulated mobile robots, one based on artificial forces and the other based on the kinetic theory of gases...
Keywords: COST REDUCTION; ROBOTICS; SOLAR SYSTEM; PAYLOADS; THERMAL PROTECTION; TEMPLATES; CERTIFICATION; MISSION PLANNING; NASA PROGRAMS; QUALIFICATIONS; RISK
|Pathway Concepts Experiment for Head-Down Synthetic Vision Displays - Prinzel, Lawrence J., III|
Eight 757 commercial airline captains flew 22 approaches using the Reno Sparks 16R Visual Arrival under simulated Category I conditions. Approaches were flown using a head-down synthetic vision display to evaluate four tunnel (''minimal'', ''box'', ''dynamic pathway'', ''dynamic crow s feet'') and three guidance (''ball'', ''tadpole'', ''follow-me aircraft'') concepts and compare their efficacy to a baseline condition (i.e., no tunnel, ball guidance)...
Keywords: AEROTHERMODYNAMICS; X-33 REUSABLE LAUNCH VEHICLE; COMPUTATIONAL FLUID DYNAMICS; THERMAL PROTECTION; INDUSTRIES; THERMAL ANALYSIS
|Detectors for optical communications: A review - Katz, J|
Detectors for optical communications in the visible and near infrared regions of the spectrum are reviewed. The three generic types of detectors described are: photomultipliers, photodiodes and avalanche photodiodes. Most of the information is applicable to other optical communications systems.
Keywords: AEROTHERMODYNAMICS; HYPERSONIC FLOW; THERMAL PROTECTION; COMPUTER PROGRAMS; INPUT; USER MANUALS (COMPUTER PROGRAMS)
|REENTRY OF SPACE CRAFT TO EARTH ATMOSPHERE - Alexander Bolonkin|
Currently reentry of USA Space Shuttles and Command Module of Lunar Ships burns a great deal of fuel to reduce reentry speed because the temperatures are too high for atmospheric braking by conventional fiber parachutes. Recently high-temperature fiber and whiskers have been produced which could be employed in a new control rectangle parachute to create the negative lift force required. Though it is not large, a light parachute decreases Shuttle speed from 8 km/s (Shuttle) and 11 km/s (Apollo Co...
Keywords: Atmospheric reentry; Space Shuttle; thermal protection of space craft; parachute braking
|An evaluation of the thermally radiant environs of a man on the lunar surface - Chapman, A. J.|
Radiative thermal energy incident effects on pressure-suited man on lunar surface
Keywords: ENVIRONMENTAL ENGINEERING; PROTECTIVE CLOTHING; SOLAR RADIATION; THERMAL ENERGY; LUNAR ENVIRONMENT; RADIATION EFFECTS; RADIATION SHIELDING; THERMAL PROTECTION
|From Abstract to Concrete Norms in Agent Institutions - Grossi, Davide|
Norms specifying constraints over institutions are stated in such a form that allows them to regulate a wide range of situations over time without need for modification. To guarantee this stability, the formulation of norms need to abstract from a variety of concrete aspects, which are instead relevant for the actual operationalization of institutions. If agent institutions are to be built, which comply with a set of abstract requirements, how can those requirements be translated in more concret...
Keywords: VIBRATION TESTS; ACCELEROMETERS; THERMAL PROTECTION; TILES; GROUND TESTS; FREQUENCY RESPONSE; COMPOSITE STRUCTURES; DYNAMIC RESPONSE; FREQUENCIES; FOAMS
|Space Station Furnace Facility. Volume 2: Requirements definition and conceptual design study - NON|
The Space Station Freedom Furnace (SSFF) Project is divided into two phases: phase 1, a definition study phase, and phase 2, a design and development phase. TBE was awarded a research study entitled, 'Space Station Furnace Facility Requirements Definition and Conceptual Design Study' on June 2, 1989. This report addresses the definition study phase only. Phase 2 is to be complete after completion of phase 1...
Keywords: COMPOSITE MATERIALS; MISSION PLANNING; REUSABLE LAUNCH VEHICLES; THERMAL PROTECTION; FLIGHT TESTS; GROUND TESTS
|Automatic recording McLeod gauge Patent - Faeth, P. A|
Automatic recording McLeod gage with three electrodes and solenoid valve connection
Keywords: CERAMICS; INSULATION; THERMAL PROTECTION; THERMODYNAMIC PROPERTIES; CHEMICAL REACTIONS; HEAT TRANSFER; PRODUCT DEVELOPMENT
|Unmanned mssr entry into mars during the 1975 manned twilight flyby - Cassidy, D. E|
No Abstract Available
Keywords: GLASS; REUSABLE HEAT SHIELDING; SPACE SHUTTLES; THERMAL INSULATION; SIMULATION; SPACECRAFT LAUNCHING; THERMAL CYCLING TESTS; THERMAL PROTECTION
|A lunar exploration program based upon Saturn-boosted systems - NON|
No Abstract Available
Keywords: ABLATION; LEADING EDGES; SPACE SHUTTLES; THERMAL PROTECTION; AERODYNAMIC HEATING; HEAT TRANSFER; TEMPERATURE CONTROL
|Fundamental Mixing and Combustion Experiments for Propelled Hypersonic Flight - Cutler, A. D.|
Two experiments have been conducted to acquire data for the validation of computational fluid dynamics (CFD) codes used in the design of supersonic combustors. The first experiment is a study of a supersonic coaxial jet into stagnant air in which the center jet is of a light gas, the coflow jet is of air, and the mixing layer between them is compressible. The jet flow field is characterized using schlieren imaging, surveys with Pitot, total temperature and gas sampling probes, and RELIEF velocim...
Keywords: HEAT FLUX; LAUNCH VEHICLES; CONVECTIVE HEAT TRANSFER; THERMAL PROTECTION; CALORIMETERS; CONDUCTIVE HEAT TRANSFER
|An Anomalous External Force on the MAP Spacecraft - Starin, Scott R.|
A common theme in discussions of the Microwave Anisotropy Probe (MAP) is the attainment of mission goals for minimal cost. One area of cost savings was a reduction in the fuel budget required. To reach orbit around the L2 notation point of the Earth-Sun system, the MAP spacecraft was guided very close to the Moon, allowing a gravity-assisted trajectory out to L2. In order to property time the lunar swing-by, MAP followed a trajectory of three-and-a-half highly elliptical phasing loops...
Keywords: AEROSPACE VEHICLES; SURVEYS; PROPULSION SYSTEM CONFIGURATIONS; RADIATION PROTECTION; THERMAL PROTECTION; SPACE COMMERCIALIZATION; CARBON NANOTUBES; TECHNOLOGY ASSESSMENT
|A heated-wire liquid-water-content instrument and results of initial flight tests in icing conditions - Neel, C. B|
No Abstract Available
Keywords: AIRFOILS; DEICERS; ICE FORMATION; PNEUMATIC CONTROL; THERMAL PROTECTION; AERODYNAMIC CHARACTERISTICS; DRAG MEASUREMENT; PRESSURE GRADIENTS; THERMOCOUPLES
|Test Report: Direct and Indirect Lightning Effects on Composite Materials - Evans, R. W|
Lightning tests were performed on composite materials as a part of an investigation of electromagnetic effects on the materials. Samples were subjected to direct and remote simulated lightning strikes. Samples included various thicknesses of graphite filament reinforced plastic (GFRP), material enhanced by expanded aluminum foil layers, and material with an aluminum honeycomb core. Shielding properties of the material and damage to the sample surfaces and joints were investigated...
Keywords: CARBON-CARBON COMPOSITES; THERMAL CONDUCTIVITY; DATA BASES; THERMAL PROTECTION; HYPERSONIC VEHICLES; HIGH TEMPERATURE ENVIRONMENTS; THICKNESS
|Average sedimentary rock rare Earth element patterns and crustal evolution: Some observations and implications from the 3800 Ma ISUA supracrustal belt, West Greenland - Dymek, R. F.|
Rare earth element (REE) data is given on a set of clastic metasediments from the 3800 Ma Isua Supracrustal belt, West Greenland. Each of two units from the same sedimentary sequence has a distinctive REE pattern, but the average of these rocks bears a very strong resemblance to the REE pattern for the North American Shale Composite (NASC), and departs considerably from previous estimates of REE patterns in Archaean sediments...
Keywords: INTERNAL FLOW; SPACE SHUTTLES; STEADY FLOW; THERMAL PROTECTION; CHANNEL FLOW; INCOMPRESSIBLE FLOW; POROUS MATERIALS
|Attitude Representations for Kalman Filtering - Markley, F. Landi|
The four-component quaternion has the lowest dimensionality possible for a globally nonsingular attitude representation, it represents the attitude matrix as a homogeneous quadratic function, and its dynamic propagation equation is bilinear in the quaternion and the angular velocity. The quaternion is required to obey a unit norm constraint, though, so Kalman filters often employ a quaternion for the global attitude estimate and a three-component representation for small errors about the estimat...
Keywords: ABLATION; THERMAL PROTECTION; SURFACE ROUGHNESS; BOUNDARY LAYER TRANSITION; LAMINAR BOUNDARY LAYER; NOSE TIPS
|Goddard Laboratory for Atmospheric Sciences, collected reprints 1978 - 1979, volume 2 - Skillman, W. C.|
Information about the Earth hydrosphere, obtained in the field and from aircraft and satellite imagery is reported. Particular emphasis is given to the use of microwave sensors in the study of soil moisture, sea ice, snow cover and atmospheric parameters associated with watersheds.
Keywords: ARRAYS; TITANIUM; FABRICATION; MANUFACTURING; PANELS; THERMAL PROTECTION; ABLATIVE MATERIALS; ASSEMBLING; HEAT SHIELDING; PRODUCTION MANAGEMENT
|Space Station Furnace Facility. Experiment/Facility Requirements Document (E/FRD), volume 2, appendix 5 - Kephart, Nanc|
The function of the Space Station Furnace Facility (SSFF) is to support materials research into the crystal growth and solidification processes of electronic and photonic materials, metals and alloys, and glasses and ceramics. To support this broad base of research requirements, the SSFF will employ a variety of furnace modules operated, regulated, and supported by a core of common subsystems. Furnace modules may be reconfigured or specifically developed to provide unique solidifcation condition...
Keywords: DURABILITY; PLANFORMS; QUALITY CONTROL; MANUFACTURING; SPACE TRANSPORTATION; THERMAL INSULATION; THERMAL PROTECTION; BONDING; COATING; HEATING; ISOLATION
|Decision Support Tool Evaluation Report for General NOAA Oil Modeling Environment(GNOME) Version 2.0 - Spruce, Joseph P.|
NASA's Earth Science Applications Directorate evaluated the potential of NASA remote sensing data and modeling products to enhance the General NOAA Oil Modeling Environment (GNOME) decision support tool. NOAA's Office of Response and Restoration (OR&R) Hazardous Materials (HAZMAT) Response Division is interested in enhancing GNOME with near-realtime (NRT) NASA remote sensing products on oceanic winds and ocean circulation...
Keywords: THERMAL PROTECTION; TECHNOLOGY ASSESSMENT; INFLATABLE STRUCTURES; REENTRY VEHICLES; AEROSHELLS; FLIGHT TESTS; SYSTEMS ENGINEERING; STABILITY; RISK
|The production of gamma rays in the galaxy - NON|
Mechanisms of galactic gamma ray production and estimates of production spectra in Milky Way
Keywords: FLAME SPRAYING; HALOGENS; INORGANIC COMPOUNDS; POLYURETHANE FOAM; RESINS; CHEMICAL REACTIONS; THERMAL PROTECTION
|Capture and Delivery of Asteroid to the Earth - Alexander Bolonkin|
Authors offer the new method for deliver the asteroid to Earth. That method is cheaper in a lot of times than a conventional method. In our method for braking apparatus and asteroid are used the kinetic energy of apparatus. This energy is used also for charging the apparatus energy storage. The small control parachute allows multiple using the Earth atmosphere for the braking the asteroid without high heating, deliver the asteroid in given point and to avoid the asteroid impact to Earth...
Keywords: Asteroid delivery to Earth; Atmospheric reentry; Space Ships; thermal protection of asteroid and space apparatus; parachute braking
|NASA Connect - XPG - X-Plane, Ratios, and TPS - NASA LaRC Office of Education|
NASA Connect segment explaining the X-Plane, scale model, and Venture Star. The video also explores a Thermal Protection System, or TPS and gives examples of this.
Keywords: NASA Connect; Velocity; Speed of Sound; Launch Vehicle; Thermal Protection System; Spacecraft; Atmosphere; X-33; Ratio; Scale; Model; Revolutions
|Computational Modeling For The Transitional Flow Over A Multi-Element Airfoil - Liou, William W.|
The transitional flow over a multi-element airfoil in a landing configuration are computed using a two equation transition model. The transition model is predictive in the sense that the transition onset is a result of the calculation and no prior knowledge of the transition location is required. The computations were performed using the INS2D) Navier-Stokes code. Overset grids are used for the three-element airfoil...
Keywords: DEBRIS; INFRARED RADIATION; ICE; HIGH SPEED PHOTOGRAPHY; SPACE MISSIONS; SPACE TRANSPORTATION SYSTEM; THERMAL PROTECTION; ICE FORMATION; CRYOGENICS; EXTERNAL TANKS
|Variational Methods in Sensitivity Analysis and Optimization for Aerodynamic Applications - Ibrahim, A. H.|
Variational methods (VM) sensitivity analysis, which is the continuous alternative to the discrete sensitivity analysis, is employed to derive the costate (adjoint) equations, the transversality conditions, and the functional sensitivity derivatives. In the derivation of the sensitivity equations, the variational methods use the generalized calculus of variations, in which the variable boundary is considered as the design function...
Keywords: THERMAL PROTECTION; TOLERANCES (MECHANICS); THERMAL SHOCK; SHOCK RESISTANCE; THERMAL STABILITY; CERAMICS; PROTECTIVE COATINGS; HIGH TEMPERATURE; CARBON-CARBON COMPOSITES; REFRACTORY MATERIALS
|Magnitude and frequency of wind speed shears and associated downdrafts - Alexander, M. B.|
Data are presented indicating the frequency of occurrence of wind shear and downdrafts together with information on the simultaneous occurrence of these two phenomena. High resolution wind profile measurements recorded at a 150 meter ground winds tower facility were used for the analysis. From instantaneous measurements during horizontal wind speeds of gale-force and below intensity, vertical motion at the 10, 60, and 150 m levels was approximately 60 percent downward and 40 percent upward...
Keywords: ABLATION; THERMAL PROTECTION; ABLATIVE MATERIALS; HEAT SHIELDING; RADIATIVE HEAT TRANSFER; REENTRY VEHICLES; AERODYNAMIC HEATING; ATMOSPHERIC ENTRY; REENTRY SHIELDING; REFRACTORY MATERIALS
|Dynamic Moire methods for detection of loosened space shuttle tiles - Snow, W. L.|
Moire fringe methods for detecting loose space shuttle tiles were investigated with a test panel consisting of a loose tile surrounded by four securely bonded tiles. The test panel was excited from 20 to 150 Hz with in-plane sinusoidal acceleration of 2 g (peak). If the shuttle orbiter can be subjected to periodic excitation of 1 to 2 g (peak) and rigid-body periodic displacements do not mask the change in the Moire pattern due to tile looseness, then the use of projected Moire fringes to detect...
Keywords: DYNAMIC RESPONSE; REUSABLE HEAT SHIELDING; NONLINEAR SYSTEMS; SPACE SHUTTLE ORBITERS; THERMAL PROTECTION; TILES; ABLATIVE MATERIALS; CONTROL EQUIPMENT; PARAMETERIZATION; REENTRY SHIELDING
|Extravehicular Mobility Unit Training Suit Symptom Study Report - Strauss, Samue|
The purpose of this study was to characterize the symptoms and injuries experienced by NASA astronauts during extravehicular activity (space walk) spacesuit training at the Neutral Buoyancy Laboratory at Ellington Field, Houston, Texas. We identified the frequency and incidence rates of symptoms by each general body location and characterized mechanisms of injury and effective countermeasures. Based on these findings a comprehensive list of recommendations was made to improve training, test prep...
Keywords: REENTRY VEHICLES; TRAJECTORY ANALYSIS; THERMAL PROTECTION; INFLATABLE STRUCTURES; AEROSHELLS; AERODYNAMIC STABILITY; STRUCTURAL ANALYSIS; AEROTHERMODYNAMICS; SOUNDING ROCKETS; LOADS (FORCES); RADAR TRACKING
|Product Distribution Theory and Semi-Coordinate Transformations - Airiau, Stephane|
Product Distribution (PD) theory is a new framework for doing distributed adaptive control of a multiagent system (MAS). We introduce the technique of ''coordinate transformations'' in PD theory gradient descent. These transformations selectively couple a few agents with each other into ''meta-agents''. Intuitively, this can be viewed as a generalization of forming binding contracts between those agents...
Keywords: AEROTHERMODYNAMICS; PROTUBERANCES; THERMAL PROTECTION; CONSTRUCTION; ELEVONS; HEAT TRANSFER; X-33 REUSABLE LAUNCH VEHICLE; ACTUATORS; CONTROL SURFACES; DEFLECTION; FLOW DISTRIBUTION
|GRB 021211 as a Faint Analogue of GRB 990123: Exploring the Similarities and Differences in the Optical Afterglows - Holland, Stephen T.|
We present BVR(sub c)JHK(sub s) photometry of the optical afterglow of the gamma-ray burst GRB 021211 taken at the Magellan, MMT, and WIYN observatories between 0.7 and 50 days after the burst. We find an intrinsic spectral slope at optical and near-infrared wavelengths of 0.69 /- 0.14 at 0.87 days. The optical decay during the first day is almost identical to that of GRB 990123 except that GRB 021211's optical afterglow was intrinsically approximately 38 times fainter and the transition from th...
Keywords: CERAMICS; HYPERVELOCITY IMPACT; REUSABLE LAUNCH VEHICLES; THERMAL PROTECTION; TILES; SYSTEMS ENGINEERING; RAIN EROSION; HONEYCOMB STRUCTURES; HIGH TEMPERATURE GASES
|Large-area silicon sheet task - Morrison, A. D|
A set of computer models was used to define a growth system configuration that was then built and used to grow web with lower thermally generated stress. Aspects of research in the edge-defined film-fed growth (EFG) method of making Si ribbon are reported. A technique was developed to determine base resistivity and carrier lifetime in semicrystalline wafers. Automated growth of 150 kg of 15 cm-dia ingot material per crucible is reviewed...
Keywords: SPACE SHUTTLE ORBITERS; TAIL ASSEMBLIES; THERMAL PROTECTION; TILES; WIND TUNNEL TESTS; ASCENT TRAJECTORIES; PRELAUNCH TESTS; REENTRY SHIELDING; TABLES (DATA)
|Structure of Boron Nitride Nanotubes: Tube Closing Vs. Chirality - Srivastava, Deepak|
The structure of boron nitride nanotubes is investigated using a generalized tight-binding molecular dynamics method. It is shown that dynamic relaxation results in a wavelike or ''rippled'' surface in which the B atoms rotate inward and the N atoms move outward, reminiscent of the surface relaxation of the III-V semiconductors. More importantly, the three different morphologies of the tube closing with flat, conical and amorphous ends, as observed in experiments, are shown to be directly relate...
Keywords: MANAGEMENT PLANNING; ABLATIVE MATERIALS; THERMAL PROTECTION; PERFORMANCE TESTS; SYSTEMS ENGINEERING; SHARP LEADING EDGES; COATING; LOW DENSITY MATERIALS
|Cars Thermometry in a Supersonic Combustor for CFD Code Validation - Cutler, A. D.|
An experiment has been conducted to acquire data for the validation of computational fluid dynamics (CFD) codes used in the design of supersonic combustors. The primary measurement technique is coherent anti-Stokes Raman spectroscopy (CARS), although surface pressures and temperatures have also been acquired. Modern- design- of-experiment techniques have been used to maximize the quality of the data set (for the given level of effort) and minimize systematic errors...
Keywords: FABRICATION; PANELS; THERMAL PROTECTION; CRYOGENIC FLUID STORAGE; CREEP ANALYSIS; LOADS (FORCES); REUSABLE LAUNCH VEHICLES; FINITE ELEMENT METHOD
|Use of antarctic analogs to support the space exploration initiative - Wharton, Robert|
This report has discussed the Space Exploration Initiative (SEI) and the U.S. Antarctic Program (USAP) in the context of assessing the potential rationale and strategy for conducting a cooperative NASA/NSF (National Science Foundation) effort. Specifically, such an effort would address shared research and data on living and conducting scientific research in isolated, confined, hostile, and remote environments...
Keywords: REUSABLE HEAT SHIELDING; REUSABLE SPACECRAFT; SPACE SHUTTLE ORBITERS; THERMAL PROTECTION; CERAMICS; INSULATION; MANUFACTURING; SPACE PROGRAMS; SYSTEMS ENGINEERING
|Preliminary performance and interface specification ground operational support system Project Apollo spacecraft /U/ - NON|
No Abstract Available
Keywords: APOLLO PROJECT; SPACECRAFT INSTRUMENTS; SPACECRAFT GUIDANCE; SPACECRAFT PROPULSION; THERMAL PROTECTION; TRAJECTORY ANALYSIS; CONFERENCES; HUMAN FACTORS ENGINEERING; SPACECRAFT COMMUNICATION; SPACECRAFT CONFIGURATIONS
|Report of the NASA Workshop on Global Wind Measurements - NON|
A summary of the workshop is presented. In the workshop the objectives were as follow: to review the requirements for wind measurements for the various atmospheric scales; to determine the capabilities and shortcomings of the current wind observing systems; to appraise each potential new wind observing system; and to establish requirements for future research and development. The papers presented addressed the following: the meteorological uses and requirements for wind measurements; the various...
Keywords: BOOSTER ROCKET ENGINES; CURTAINS; ROCKET ENGINE DESIGN; SOLID PROPELLANT ROCKET ENGINES; THERMAL ANALYSIS; THERMAL PROTECTION; THERMODYNAMIC PROPERTIES; COMPUTER TECHNIQUES; ESTIMATING
|ACTS mobile propagation campaign - Goldhirsh, Julius|
Preliminary results are presented for three propagation measurement campaigns involving a mobile receiving laboratory and 20 GHz transmissions from the Advanced Communications Technology Satellite (ACTS). Four 1994 campaigns were executed during weekly periods in and around Austin, Texas in February and May, in Central Maryland during March, and in Fairbanks, Alaska and environs in June. Measurements tested the following effects at 20 GHz: (1) attenuation due to roadside trees with and without f...
Keywords: CLEAN ROOMS; CONTROLLED ATMOSPHERES; OPTICAL EQUIPMENT; SAMPLING; THERMAL PROTECTION; CLEANLINESS; CONTAMINATION; FABRICATION; HUBBLE SPACE TELESCOPE; PROVING; SHROUDS; SIMULATORS; ASTRONAUT TRAINING